Sir,

Optic disc swelling in a child, with no other features suggestive of raised intracranial pressure is a challenging clinical scenario. These children frequently undergo invasive investigations, such as neuroimaging and lumbar puncture, even though the clinical suspicion of serious pathology is low.

In this study, we report a new clinical presentation of benign optic disc swelling in five siblings of two families, where optic disc drusen were not present at first presentation, but developed many months later as shown on serial B-scan ultrasonography. We have termed this unusual presentation ‘familial pseudopapilloedema’.

Five children (two siblings from one family and three siblings from another family) underwent examination and B-scan ultrasonography at first presentation and at all subsequent examinations. Age range at first presentation was 18 months to 12 years with a mean of 6.5 years. The male to female ratio was 4 : 1. All five children had clinically apparent optic disc swelling without other ophthalmoscopic features of papilloedema (retinal nerve fibre layer swelling, surrounding disc haemorrhages, cotton wool spots, hyperemia, venous congestion, Patton's lines, or exudates1). None had any symptoms suggestive of raised intracranial pressure, other neurological disease, or systemic upset (Table 1).

Table 1 Summary table showing each of the five children's age, reason for presentation, vision, refraction, and investigations
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Serial B-scan ultrasonography showed no drusen at the first visit. However, all children developed small linear drusen at the optic disc over time (Figure 1). The mean time for development of drusen detectable on B-scan was 2.7 years. At no point was there optic nerve sheath dilation on B-scan. In two children, CT scans were conducted and reported as normal. A CT scan was avoided in three children because of the absence of optic nerve sheath swelling on sonography, the absence of symptoms of raised intracranial pressure and normal visual function.2, 3

Figure 1
figure 1

B-scan of small linear disc drusen (arrow) in one of the subjects.

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Discussion

This is the first description of development of optic drusen in related children with pseudopapilloedema.4, 5 We found that reassuring symptomatology, the absence of optic nerve-sheath swelling on B-scans and a positive family history of pseudopapilloedema to be very helpful in excluding serious intracranial pathology, as well as reducing the need for lumbar punctures and CT scans.